焦耳定律是初中物理“电功和电功率”一章中的重要实验,现有教具焦耳定律演示仪在具体教学演示中效果不理想。本人经过多次使用,认为主要存在以下不足:1.仪器中阻值不同的电阻丝用外观完全一样的同一种电阻(只是阻值不同),因标称值的字太小,使学生不易区分哪个电阻大哪个电阻小。2.在仪器中放入煤油后,实验要等很长时间才有反 Joule’s law is an important experiment in the chapter of junior high school physics“electric power and electric power”. The existing Joy’s law demonstrator is not ideal in teaching demonstration. After several uses, I believe that there are mainly the following deficiencies: 1. The resistance wire with different resistance in the instrument uses the same resistance with the same appearance (only the resistance is different), because the word of the nominal value is too small, making it difficult for students to distinguish Which resistor is larger and which resistor is smaller. 2. After putting kerosene into the instrument, the experiment must wait a long time before it is reversed.